1. Technical Field
The present invention relates to a multi-wavelength light source device for emitting a plurality of light beams composed of, for example, red light, green light, and blue light.
2. Related Art
In recent years, coherent light sources have become essential to image display devices, the optical communication field, the medical field, and the measurement field including microscopes. However, laser sources have a disadvantage of having coherency. According to this disadvantage, since an interference light appears on a projection surface on which the laser beam is projected as the speckle noise, some countermeasures to the speckle noise becomes necessary in order for displaying a high-resolution image.
Therefore, as a method of removing the speckle noise, it has been proposed to arrange a plurality of light emitting elements having center wavelengths slightly different from each other as design values in an array arrangement (see e.g., JP-T-2004-503923, the term “JP-T” as used herein means a published Japanese translation of a PCT patent application). In such a laser source, reduction of the speckle noise is achieved by differentiating the center wavelengths to increase the spectral line width.
However, also in the laser source of the related art described above, it is still expected to surely provide a wide color gamut as a feature of the laser sources while reducing the speckle noise.